The secret of blue is well kept. Blue comes from far away. On its way, it hardens and changes into a mountain. The cicada works at it. The birds assist. In reality, one doesn’t know. One speaks of Prussian blue. In Naples, the virgin stays in the cracks of walls when the sky recedes. But it’s all a mystery. The mystery of sapphire, mystery of Sainte Vierge, mystery of the siphon, mystery of the sailor’s collar, mystery of the blue rays that blind and your blue eye which goes through my heart.
— Jean Cocteau, from “The Secret of Blue,” Tempest of Stars: Selected Poems (Enitharmon Press, 1997)